feat(app): implement K8sPod payload support in buildPodSpec

app/internal/k8s/app_client.go

@@ -26,6 +26,7 @@ import (
 	"github.com/flyteorg/flyte/v2/app/internal/config"
 	"github.com/flyteorg/flyte/v2/flytestdlib/k8s"
 	"github.com/flyteorg/flyte/v2/flytestdlib/logger"
+	"github.com/flyteorg/flyte/v2/flytestdlib/utils"
 	flyteapp "github.com/flyteorg/flyte/v2/gen/go/flyteidl2/app"
 	flytecore "github.com/flyteorg/flyte/v2/gen/go/flyteidl2/core"
 )
@@ -582,7 +583,7 @@ func (c *AppK8sClient) buildKService(app *flyteapp.App) (*servingv1.Service, err
 }
 
 // buildPodSpec constructs a corev1.PodSpec from an App Spec.
-// Supports Container payload only for now; K8sPod support can be added in a follow-up.
+// Supports Container and K8sPod payloads.
 func buildPodSpec(spec *flyteapp.Spec) (corev1.PodSpec, error) {
 	switch p := spec.GetAppPayload().(type) {
 	case *flyteapp.Spec_Container:
@@ -612,9 +613,18 @@ func buildPodSpec(spec *flyteapp.Spec) (corev1.PodSpec, error) {
 		}, nil
 
 	case *flyteapp.Spec_Pod:
-		// K8sPod payloads are not yet supported — the pod spec serialization
-		// from flyteplugins is needed for a complete implementation.
-		return corev1.PodSpec{}, fmt.Errorf("K8sPod app payload is not yet supported")
+		pod := p.Pod
+		if pod == nil || pod.GetPodSpec() == nil {
+			return corev1.PodSpec{}, fmt.Errorf("K8sPod app payload has no pod spec")
+		}
+		var podSpec corev1.PodSpec
+		if err := utils.UnmarshalStructToObj(pod.GetPodSpec(), &podSpec); err != nil {
+			return corev1.PodSpec{}, fmt.Errorf("failed to unmarshal K8sPod spec: %w", err)
+		}
+		if podSpec.EnableServiceLinks == nil {
+			podSpec.EnableServiceLinks = boolPtr(false)
+		}
+		return podSpec, nil
 
 	default:
 		return corev1.PodSpec{}, fmt.Errorf("app spec has no payload (container or pod required)")

app/internal/k8s/app_client_test.go

@@ -4,9 +4,12 @@ import (
 	"context"
 	"crypto/sha256"
 	"encoding/hex"
+	"encoding/json"
 	"testing"
 	"time"
 
+	"google.golang.org/protobuf/types/known/structpb"
+
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	corev1 "k8s.io/api/core/v1"
@@ -740,3 +743,139 @@ func TestKserviceToStatus_Messages(t *testing.T) {
 		})
 	}
 }
+
+
+// transformStructToStructPB converts an arbitrary Go object into a *structpb.Struct
+// by round-tripping through JSON. It fails the test on any marshaling error.
+func transformStructToStructPB(t *testing.T, obj interface{}) *structpb.Struct {
+	t.Helper()
+	data, err := json.Marshal(obj)
+	require.NoError(t, err)
+	m := make(map[string]interface{})
+	err = json.Unmarshal(data, &m)
+	require.NoError(t, err)
+	s, err := structpb.NewStruct(m)
+	require.NoError(t, err)
+	return s
+}
+
+func TestBuildPodSpec_Container(t *testing.T) {
+	spec := &flyteapp.Spec{
+		AppPayload: &flyteapp.Spec_Container{
+			Container: &flytecoreapp.Container{
+				Image:   "nginx:latest",
+				Command: []string{"nginx"},
+				Args:    []string{"-g", "daemon off;"},
+				Env: []*flytecoreapp.KeyValuePair{
+					{Key: "FOO", Value: "bar"},
+				},
+				Ports: []*flytecoreapp.ContainerPort{
+					{ContainerPort: 8080, Name: "http"},
+				},
+				Resources: &flytecoreapp.Resources{
+					Requests: []*flytecoreapp.Resources_ResourceEntry{
+						{Name: flytecoreapp.Resources_CPU, Value: "100m"},
+						{Name: flytecoreapp.Resources_MEMORY, Value: "128Mi"},
+					},
+				},
+			},
+		},
+	}
+
+	podSpec, err := buildPodSpec(spec)
+	require.NoError(t, err)
+	require.Len(t, podSpec.Containers, 1)
+	assert.Equal(t, "app", podSpec.Containers[0].Name)
+	assert.Equal(t, "nginx:latest", podSpec.Containers[0].Image)
+	assert.Equal(t, []string{"nginx"}, podSpec.Containers[0].Command)
+	assert.Equal(t, []string{"-g", "daemon off;"}, podSpec.Containers[0].Args)
+	assert.Equal(t, []corev1.EnvVar{{Name: "FOO", Value: "bar"}}, podSpec.Containers[0].Env)
+	assert.Equal(t, []corev1.ContainerPort{{ContainerPort: 8080, Name: "http"}}, podSpec.Containers[0].Ports)
+	assert.Equal(t, "100m", podSpec.Containers[0].Resources.Requests.Cpu().String())
+	assert.Equal(t, "128Mi", podSpec.Containers[0].Resources.Requests.Memory().String())
+	assert.NotNil(t, podSpec.EnableServiceLinks)
+	assert.False(t, *podSpec.EnableServiceLinks)
+}
+
+func TestBuildPodSpec_Pod(t *testing.T) {
+	podSpecMap := map[string]interface{}{
+		"containers": []map[string]interface{}{
+			{
+				"name":  "app",
+				"image": "my-image:v1",
+				"ports": []map[string]interface{}{
+					{"containerPort": float64(80), "name": "http"},
+				},
+				"resources": map[string]interface{}{
+					"requests": map[string]interface{}{
+						"cpu":    "250m",
+						"memory": "256Mi",
+					},
+				},
+			},
+		},
+		"restartPolicy": "Always",
+	}
+
+	spec := &flyteapp.Spec{
+		AppPayload: &flyteapp.Spec_Pod{
+			Pod: &flytecoreapp.K8SPod{
+				PodSpec: transformStructToStructPB(t, podSpecMap),
+			},
+		},
+	}
+
+	podSpec, err := buildPodSpec(spec)
+	require.NoError(t, err)
+	require.Len(t, podSpec.Containers, 1)
+	assert.Equal(t, "app", podSpec.Containers[0].Name)
+	assert.Equal(t, "my-image:v1", podSpec.Containers[0].Image)
+	assert.Len(t, podSpec.Containers[0].Ports, 1)
+	assert.Equal(t, int32(80), podSpec.Containers[0].Ports[0].ContainerPort)
+	assert.Equal(t, "250m", podSpec.Containers[0].Resources.Requests.Cpu().String())
+	assert.Equal(t, "256Mi", podSpec.Containers[0].Resources.Requests.Memory().String())
+	assert.Equal(t, corev1.RestartPolicyAlways, podSpec.RestartPolicy)
+	assert.NotNil(t, podSpec.EnableServiceLinks)
+	assert.False(t, *podSpec.EnableServiceLinks)
+}
+
+func TestBuildPodSpec_Pod_NilPodSpec(t *testing.T) {
+	spec := &flyteapp.Spec{
+		AppPayload: &flyteapp.Spec_Pod{
+			Pod: &flytecoreapp.K8SPod{},
+		},
+	}
+
+	_, err := buildPodSpec(spec)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "has no pod spec")
+}
+
+func TestBuildPodSpec_Pod_InvalidJSON(t *testing.T) {
+	// Create a Struct that cannot be unmarshaled into corev1.PodSpec.
+	// "containers" must be an array, not a string.
+	s := &structpb.Struct{
+		Fields: map[string]*structpb.Value{
+			"containers": {Kind: &structpb.Value_StringValue{StringValue: "not-an-array"}},
+		},
+	}
+
+	spec := &flyteapp.Spec{
+		AppPayload: &flyteapp.Spec_Pod{
+			Pod: &flytecoreapp.K8SPod{
+				PodSpec: s,
+			},
+		},
+	}
+
+	_, err := buildPodSpec(spec)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "failed to unmarshal K8sPod spec")
+}
+
+func TestBuildPodSpec_NoPayload(t *testing.T) {
+	spec := &flyteapp.Spec{}
+	_, err := buildPodSpec(spec)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "app spec has no payload")
+}